In the waning days of 1948, during the Huaihai Campaign of the Chinese Civil War, the Gu Zidi of the 9th Company, 139th Regiment of the PLA leads a bold push to seize a town held by the NRA, only to endure brutal, concentrated fire that leaves the unit badly mauled. Fueled by anger over the death of his political commissar, he makes a perilous attempt to execute surrendering NRA soldiers, a decision that lands him in the brig for three days under the watch of Col. Liu Zeshui. While behind bars, he forms an uneasy bond with Wang Jincun, a foot soldier and former teacher who has been jailed for cowardice, a reminder that courage and culpability can wear different faces in war.
When Gu is released, he and his 46 surviving men are sent to defend a coal mine perched on the bank of the Wen River near Tai'an, in the heart of Shandong Province. They are ordered to hold their ground until a distant bugle call signals a regrouping. With Liu’s permission, the educated Wang steps into the role of the 9th Company’s new political commissar, aiming to steady the ranks with ideas and faith. Almost immediately, the unit endures a brutal onslaught from NRA forces, fending off infantry, supporting armor, and even destroying two enemy tanks. The company dwindles to a handful of men, and as some soldiers claim to hear a distant bugle, Captain Gu, who has been temporarily deafened by an explosion, refuses to believe that relief is near and orders everyone to fight to the last man. In the end, the entire 9th Company is wiped out except for Gu, who is knocked unconscious by a tank shell.
The PLA eventually recaptures the area and discovers Gu unconscious, wearing a NRA uniform he had stolen in a bid to survive, not long after he had secretly bombed an enemy fuel depot. He tries to explain that he is a PLA captain who pretended to be an enemy soldier to procure food, but the army has undergone reorganization in the meantime, and there is little memory of the 139th Regiment. The hospital becomes a cold arena of doubt, and Gu is treated with suspicion as a possible deserter rather than a survivor of a doomed unit.
As the Korean War looms in 1950, Gu volunteers to fight again as a foot soldier with the People’s Volunteer Army. On a dangerous artillery-spotting mission, he and his team disguise themselves as soldiers from the RoK Army’s 6th Infantry Division. Gu risked his life to shield his unit’s commander, Lieutenant Zhao Erdou, after Zhao accidentally triggers a hidden anti-personnel mine. Gu hunkers down under the blast, preserves Zhao’s life, but loses his right eye in the explosion. The two men grow close, and Zhao becomes a steadfast ally who backs Gu’s efforts to earn rightful recognition for the 9th Company’s sacrifices.
Back home after the fighting, Gu makes a long, quiet pilgrimage to the Wen River battlefield, hoping to locate how the mines and the fateful day unfolded. He finds the mine seems to have reopened and the old entry buried beneath new coal. He also encounters Wang’s widow and convinces her to marry Zhao, weaving a fragile thread of personal resolution into the national saga. Zhao later uncovers the tomb of Col. Liu Zeshui, where a caretaker—an old subordinate who survived the war but lost an arm—confirms that the bugle call was never sounded. The revelation shatters the narrative Gu carried for so long: the 9th Company had been sacrificed to buy time for the rest of the regiment.
Armed with this knowledge, Gu sets up camp at the mine and, with miners’ protests in the background, begins a painstaking effort to recover his fallen comrades. A surviving former officer of the 139th Regiment steps forward a month later to corroborate the unit’s deeds, and the PLA issues an official recognition for the 9th Company. Yet Gu remains tormented by the missing bodies. A powerful flashback reveals the cruel sacrifice: as enemy forces closed in, Gu and Wang bury their comrades deep inside the mine; Wang, mortally wounded, detonates the mine entrance to prevent its capture, sacrificing himself in the process.
In the years that follow, the remains of the other soldiers are eventually found during an irrigation project excavation. The PLA erects a monument near the site and holds a full military funeral for the men of the 9th Company. At last, Gu finds a measure of peace. The closing titles recount that he died in 1987, at the age of 71. Orphaned at three months old by famine, he had been discovered by a shoemaker in a millet field and named Gu Zidi, a name that now carries the weight of a long, hard-earned memory.
